WIP: update docs to new frontend/UI
### TLDR: Update `datasets` `docs` to the new syntax & frontend (as how it looks on [hf.co/transformers](https://huggingface.co/docs/transformers/index))

## Checklist

- [ ] update datasets docs to new syntax (should call `doc-builder convert`) (this PR)
- [x] discuss `@property` methods frontend https://github.com/huggingface/doc-builder/pull/87
- [x] discuss `inject_arrow_table_documentation` (this PR) https://github.com/huggingface/datasets/pull/3690#discussion_r801847860
- [x] update datasets docs path on moon-landing https://github.com/huggingface/moon-landing/pull/2089
- [ ] update nginx `docs/datasets` to route to moon-landing (do similar to internal repo # 81)
- [x] convert pyarrow docstring from Numpydoc style to groups style  https://github.com/huggingface/doc-builder/pull/89(https://stackoverflow.com/a/24385103/6558628)
- [x] handle `Raises` section on frontend and doc-builder https://github.com/huggingface/doc-builder/pull/86
- [x] check imgs path (this PR) (nothing to update here)
- [ ] delete sphinx related files (this PR)
- [ ] update github actions (doc quality check & PR doc)
- [x] doc exaples block has to follow format `Examples::` https://github.com/huggingface/datasets/pull/3693
- [ ] add `versions.yml` in doc-build and doc-build-dev repos